Rainfall

The rainfall at the South Australian Regional Office, Kent Town, for July 2009 was 109.0 mm recorded (Please note: This is the official reading from the manual gauge at the South Australian Regional Office, for which long term records exist. Observations for the month in progress available elsewhere on our website may differ due to being recorded on automatic instruments for which only short records are available.) on 18 days, which is very much above the long term average of 74.8 mm. This has been the wettest July since 1996 when 115.0 mm was recorded. The highest July rainfall occurred in 1986 with 159.8 mm.

Over the metropolitan and hills area the rainfall recordings were predominantly above average to very much above average than the long-term July averages. Rainfall totals were generally between 60 mm and 90 mm over the coastal and northern plains areas, however, over the higher parts of the Adelaide Hills totals in excess of 200 mm were recorded at many locations. The highest rainfall total was 256.6 mm recorded at Uraidla in the Adelaide Hills.

For the first seven months of the year 321.0 mm have been recorded at the South Australian Regional Office. The long-term average is 316.6 mm for the same period.

Temperature

The average temperature over metropolitan Adelaide and adjacent hills area was above average for July, grading from about 1.0°C above the long-term average throughout metropolitan Adelaide to about 1.5°C above in the Adelaide Hills.

The mean maximum temperature recorded at the South Australian Regional Office (Kent Town) for July 2009 was 15.8°C, which is 0.5°C above the long-term mean maximum temperature. Last year, in contrast, was 0.5°C below the long-term July mean maximum temperature.

The hottest maximum temperature recorded in the Adelaide metropolitan and hills area was 21.7°C on the 20th at the South Australian Regional Office (Kent Town).

The mean minimum temperature for July 2009 at the South Australian Regional Office (Kent Town) was 9.0°C, which is 1.6°C above the normal July mean minimum temperature of 7.4°C. This is the warmest July average minimum temperature since 1975, at the South Australian Regional Office, and is the equal sixth highest since temperature records began in 1887. The lowest recorded average minimum temperature is 4.8°C in 1899. July, last year, the mean minimum temperature was 7.4°C.

The coldest minimum temperature recorded in the Adelaide metropolitan and hills area was −0.1°C on the 7th at Edinburgh, whilst the warmest night was 14.5°C at the South Australian Regional Office, at Kent Town, on the 21st.

Severe Thunderstorm

A small supercell spawned a significant tornado in the southern Adelaide suburb of Port Noarlunga on 11 July. The tornado damage track was 2.7 km long. At the western end, the tornado damaged five houses, demolished a shed, shifted cars, and hurled iron and glass debris across an oval during a football match. One person on the oval was injured. Substantial tree damage occurred along the eastern section of the track. Damage was rated to be at the high end of category F1 or possibly the low end of category F2 on the Fujita tornado category scale.

Notes

This statement has been prepared based on information available at
3 pm on Friday 31 July 2009.
Some checks have been made on the data, but it is possible that results will change
as new information becomes available.

Averages are long-term means based on observations from
all available years of record, which vary widely from site to site.
They are not shown for sites with less than 20 years of record, as they cannot then be calculated reliably.
The median
is sometimes more representative than the
mean
of long-term average rain.

The Rank indicates how rainfall this time compares with the climate record for the site,
based on the
decile ranking
(very low rainfall is in decile 1, low in decile 2 or 3,
average in decile 4 to 7, high in decile 8 or 9
and very high is in decile 10).
The Fraction of average shows how much rain has fallen this time as a
percentage of the long-term mean.